Scott Wood <[EMAIL PROTECTED]> said:
> Alexandros Kostopoulos wrote:
> > I've noticed the following: In function pci_process_bridge_OF_ranges,
> > when parsing the ranges for MEM and I/O space, the res->start for mem
> > is correctly set to ranges[na+2], which is the cpu address in the
> > ranges property. However, in I/O related code, res->start is set to
> > ranges[2], which is in the PCI address field of the ranges property
> > (and in my case is 0, as is also for the mpc8272ads case as well).
> > Thus, the res->start of the I/O of the bridge is 0, which leads to the
> > first device with I/O space (a davicom ethernet device) been also
> > assigned a I/O region starting at 0. Finally, the dmfe (davicom
> > ethernet driver over PCI) fails with "dmfe: I/O base is zero". So, is
> > the implementation of pci_process_bridge_OF_ranges correct ? shouldn't
> > res->start = ranges[na+2] for I/O as well?
>
> Ideally, yes -- but currently IO-space resources are relative to the
> start of the primary bus's IO-space.
>
> As a workaround, try not setting the primary flag when calling
> pci_process_bridge_OF_ranges. Note that this means that any legacy I/O
> ports that may exist on cards you plug in (such as VGA cards) will not
> be found.
>
> The proper solution is probably to refuse pre-existing BARs that are
> lower than PCIBIOS_MIN_IO, and/or provide a flag to tell the PCI layer
> to completely ignore pre-existing BARs.
I was referring to the allocation of primary bus' IO space based on the
device tree. I understand that IO-space resources are relative to the start
of the primary bus' IO space. But I think the primary bus IO space allocation
itself is broken. Let me explain with an example:
In mpc8272ads.dts, the ranges property for pci is:
ranges = <42000000 0 80000000 80000000 0 20000000
02000000 0 a0000000 a0000000 0 20000000
01000000 0 00000000 f6000000 0 02000000>;
The third obviously corresponds to IO space. So, shouldn't the res->start for
the host bridge be set to f6000000 ? Because, currently, based on what I've
described in my previous mail, it gets set to 0. It seems to me like a matter
of incorrect parsing of the device tree from pci_process_bridge_OF_ranges()
for IO space. Or am I missing something else here, and it should actually be
0?
thanks
Alex
>
> -Scott
>
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